A Turbo-Boost for Your Arm

Dec. 13, 2013 6:53 p.m. ET

Powered exoskeletons, basically wearable robotic limbs, have been the stuff of science fiction and scientific research for years. But these external bodily helpers tend to be expensive—one reason why they remain largely experimental.

Now, though, engineering students at the University of Pennsylvania have developed a lightweight exoskeletal right arm for less than $2,000, powered by a battery in a backpack weighing about 18 pounds....